The present invention relates to a process for removing cations of an alkaline earth metal species from an aqueous solution with an ion exchanger material that is a cation exchanger or contains one, and for subsequently regenerating the loaded or exhausted ion exchanger material.
For a long time it has been known that alkaline earth ions can be removed from raw water by means of cation exchangers, in particular with sodium-loaded cation exchangers. In this process, sodium ions on the exchanger are exchanged with the alkaline earth ions in the raw water. However, with the currently known processes it is not possible to target and selectively remove an alkaline earth species from raw water which contains several species of alkaline earth ions.